116 CLASS ITT. 



Polyps numerous, sessile, prehensile organs with simply spiral 

 nettle-nodes. Bracts claviform with special prehensile organs small, 

 knotted. At regular distances below the swimming column a 

 collection of polyps with all these appendages surround the stem. 



Note. In no other genus of PJtyssophoridce are feelers met with on the 

 part of the stem which supports the swimming bells. 



Stcphanomia uvaria LESSON belongs to this genus : KOELLIKER, Die 

 Schwimmpolypen, s. 18. See GEGENBAUER'S description of a complete 

 specimen of it, and figure, Zeitschrift fiir wissensch. Zool. V. s. 319 3-24. 

 PL xvin. fig. i. 



Family III. Hippopodidce. Colonies of swimming Polyps, 

 without swimming bladder, with short common stem, the swim- 

 ming column not formed of bells. 



Hippopodius QUOY and GAIM. ESCHSCH. The swimming 

 column formed of bracts in two rows, and covering one another 

 imbricately, with filiform short stem, to which the polyps with 

 their prehensive and sexual organs are attached. 



Sp. Hippop. luteus, Ann. des Sc. not. x. 1827, s. 172, 173, PL iv. A. 

 GUERIN Iconogr., Zooph. PL xix. fig. 4. Hippopod. neapolitanus KOELL. 

 Die Siphon, pp. 28 31. Tab. vi. figs, i 5. 



Vogtia KOELL. 



Sp. Vogtia pentacantha KOELL. Die <S%A. von Messina, s. 31, 32. Tab. 



VIII. 



Family IV. Diphyidce. Locomotive apparatus of the colony 

 two distinct cartilagineo-gelatinous transparent pieces affixed to the 

 upper part of a thin cylindrical common stem. The stem begin- 

 ning in the substance of the anterior piece passes in a groove of the 

 posterior between the two, and then gives attachment to groups 

 consisting of a single polyp and its appendages.] 



This family includes certain marine animals, transparent as glass, 

 which swim by means of the contraction of hollow organs filled 

 with water ; it has the genus Diphyes for its type, which was first 

 formed by CUVIER in the first edition of his Rdgne Animal, iv. p. 61. 

 This genus rested on a species discovered by BORY DE SAINT- 

 VINCENT at the beginning of this century (1801), in the South 

 Atlantic Ocean, and described under the name of Salpa bipartite; 

 see his Voyage dans les quatre principales ttes des Mers d'Afrique, 





